Ive been using a large unfitted bed sheet. pain is its impossible to get completely wrinkle free, no matter how much you iron it. But you can digitally iron it but thats time consuming. But if you want a pure white sheet, give it more light and blow out the wrinkles.
I have a vinyl backdrop that has plenty of small wrinkles. The trick to to cross light it (one light on either side), that way I get a nice clean white background.
I still havent mastered the art of evenly lighting the background from portable flashes. Theres always the bright spot there the flash is closest and then fades out noticiably. Put them on opposite sides and the outside of the bg is the brightest and the center where they meet is noticably darker in the pictures. this isnt to much of a problem with white but its a problem with blue and red. And with red, a red hue comes off of the bg and hits the subject and gives them a reddish cast.
ive been buying two bed sheets for each color I want to use, and put one on the ground and one on the backdrop, then clean up the seam in photoshop.
I'd think that using paper would be a much easier solution...unless you have to travel with the paper.
As Keith always points out, you can get rolls of paper from
B&H for as little as $35 (I think)...and because he's a member of NAPP, he gets free shipping. You'd be hard pressed to find two good sized bed sheets for that.